forming an essential foundation or starting point; fundamental

certain basic rules must be obeyed

the laying down of arms is basic to the agreement

having the properties of a base, or containing a base; having a pH above 7

these salts yield basic solutions comparable in strength with the mineral alkalis

the essential facts or principles of a subject or skill

I learnt the basics of programming on a course

teachers are going back to basics to encourage pupils to learn English

a simple high-level computer programming language that uses familiar English words, designed for beginners and formerly used widely

you could write your own software in the BASIC programming language