(transitive) To provide support to; to further the progress of; to help; to assist. / (climbing) To climb with the use of aids such as pitons.

(uncountable) Help; assistance; succor, relief. / (countable) A helper; an assistant. / (countable) Something which helps; a material source of help.

Initialism of Agency for International Development.

(UK, informal) for the sake of, for (usually placed at the end of a question when quizzing a person about why they have done something)

(medicine, acronym) Acquired immune deficiency syndrome.

(slang, vulgar) Extremely annoying or frustrating.

An assistant. / (military) An officer who acts as assistant to a more senior one; an aide-de-camp.

plural of aide

simple past tense and past participle of aid

The act of one who aids or assists.