良好(liáng hǎo) - good, favourable, satisfactory in Mandarin

良好 (liánghǎo) is the formal, written "good". It belongs to school reports, medical notes, machine inspections, diplomatic statements and company reviews. The pairings are fixed and worth memorising as blocks: 良好的习惯, 良好的关系, 良好的环境, 状态良好.

In the Chinese grading system it also has a precise value. Marks run 优秀, 良好, 及格, 不及格, so 良好 is roughly a B: good, but explicitly not the top band. That specificity is invisible if you only learn it as "good", and it explains the slightly cool feel the word has.

The trap is using it in conversation. If a friend asks how the food was, the answer is 很好吃 or 不错, never 良好. Saying 这个菜很良好 is like appraising a plate of noodles in the register of a surveyor's report. Keep 良好 for writing and for anything with a form to fill in, and let 好 and 不错 handle real life.