1. good; excellent; fine; nice; pleasant; agreeable
also いい (all senses)
私、兄さんの妹で本当によかった。I am really glad to be my older brother's younger sister.
2. sufficient; enough; ready; prepared
3. profitable (deal, business offer, etc.); beneficial
4. OK; all right; fine; no problem
as て(も)良い, と(も)良い, etc.; indicates permission or compromise
婚約を破棄したければ破棄してもよい。If you want to break off the engagement, you may do so.
5. easy to ...
after the -masu stem of a verb