in|fer|no / I nfɜː r noʊ/ (infernos ) N‑COUNT [usu sing] If you refer to a fire as an inferno , you mean that it is burning fiercely and causing great destruction. [JOURNALISM ] □ Rescue workers fought to get to victims inside the inferno.
in|fer|tile / I nfɜː r ta I l, [AM ] -t ə l/
1 ADJ A person or animal that is infertile is unable to produce babies. □ According to one survey, one woman in eight is infertile. ● in|fer|til|ity / I nfɜː r t I l I ti/ N‑UNCOUNT □ Male infertility is becoming commonplace.
2 ADJ Infertile soil is of poor quality so that plants cannot grow in it. □ The polluted waste is often dumped, making the surrounding land infertile.
in|fest / I nfe st/ (infests , infesting , infested )
1 VERB When creatures such as insects or rats infest plants or a place, they are present in large numbers and cause damage. □ [V n] …pests like aphids which infest cereal crops. ● in|fest|ed ADJ □ [+ with ] The prison is infested with rats. ● -infested COMB □ …the rat-infested slums where the plague flourished. ● in|fes|ta|tion / I nfeste I ʃ ə n/ (infestations ) N‑VAR [oft n N ] □ The premises were treated for cockroach infestation. [Also + of ]
2 VERB If you say that people or things you disapprove of or regard as dangerous are infesting a place, you mean that there are large numbers of them in that place. [DISAPPROVAL ] □ [V n] Crime and drugs are infesting the inner cities. ● in|fest|ed ADJ □ [+ with ] The road further south was infested with bandits. ● -infested COMB □ …the shark-infested waters of the Great Barrier Reef.
in|fi|del / I nf I d ə l/ (infidels ) N‑COUNT If one person refers to another as an infidel , the first person is hostile towards the second person because that person has a different religion or has no religion. [LITERARY , DISAPPROVAL ] □ …a holy war, to drive the infidels and the non-believers out of this holy land. ● ADJ [ADJ n] Infidel is also an adjective. □ He promised to continue the fight against infidel forces.
in|fi|del|ity / I nf I de l I ti/ (infidelities ) N‑VAR Infidelity occurs when a person who is married or in a steady relationship has sex with another person. □ George ignored his partner's infidelities.
in|fighting / I nfa I t I ŋ/ also in-fighting N‑UNCOUNT Infighting is quarrelling and competition between members of the same group or organization. □ [+ between ] …in-fighting between right-wingers and moderates in the party.
in|fill / I nf I l/ (infills , infilling , infilled ) VERB To infill a hollow place or gap means to fill it. [mainly BRIT ] □ [be V -ed] The entrance to the cave was infilled by the landowner. □ [V ] It is wise to start infilling with a layer of gravel for drainage. [Also V n] in AM, use fill in
in|fil|trate / I nf I ltre I t/ (infiltrates , infiltrating , infiltrated )
1 VERB If people infiltrate a place or organization, or infiltrate into it, they enter it secretly in order to spy on it or influence it. □ [V n] Activists had infiltrated the student movement. □ [V + into ] A reporter tried to infiltrate into the prison. ● in|fil|tra|tion / I nf I ltre I ʃ ə n/ (infiltrations ) N‑VAR □ [+ by ] …an inquiry into alleged infiltration by the far left group.
2 VERB To infiltrate people into a place or organization means to get them into it secretly in order to spy on it or influence it. □ [V n + into ] Some countries have infiltrated their agents into the Republic.
in|fil|tra|tor / I nf I ltre I tə r / (infiltrators ) N‑COUNT An infiltrator is a person who has infiltrated a place or organization.
infin. infin. is an abbreviation for infinitive .
in|fi|nite / I nf I n I t/
1 ADJ If you describe something as infinite , you are emphasizing that it is extremely great in amount or degree. [EMPHASIS ] □ …an infinite variety of landscapes. □ The choice is infinite. ● in|fi|nite|ly ADV [ADV adj/adv] □ His design was infinitely better than anything I could have done.
2 ADJ Something that is infinite has no limit, end, or edge. □ Obviously, no company has infinite resources. ● in|fi|nite|ly ADV [ADV with v] □ A centimeter can be infinitely divided into smaller units.
in|fini|tesi|mal / I nf I n I te s I m ə l/ ADJ Something that is infinitesimal is extremely small. [FORMAL ] □ …mineral substances present in infinitesimal amounts in the soil.
in|fini|tive / I nf I n I t I v/ (infinitives ) N‑COUNT The infinitive of a verb is the basic form, for example 'do', 'be', 'take', and 'eat'. The infinitive is often used with 'to' in front of it.
in|fi|ni|tum / I nf I na I təm/ → see ad infinitum
in|fin|ity / I nf I n I ti/
1 N‑UNCOUNT Infinity is a number that is larger than any other number and can never be given an exact value. □ These permutations multiply towards infinity.
2 N‑UNCOUNT Infinity is a point that is further away than any other point and can never be reached. □ …the darkness of a starless night stretching to infinity.
in|firm / I nfɜː r m/ ADJ A person who is infirm is weak or ill, and usually old. [FORMAL ] □ …her aging, infirm husband. ● N‑PLURAL The infirm are people who are infirm. □ We are here to protect and assist the weak and infirm. ● in|fir|mity / I nfɜː r m I ti/ (infirmities ) N‑VAR □ In spite of his age and infirmity, he still writes plays and novels.