Definitions:

1. Agreed or acceptable. ADJECTIVE
   • If it's 'ok' with you, I'll come over tomorrow instead.
2. an endorsement noun
   • We got the ok from the president.
3. being satisfactory or in satisfactory condition adjective
   • The watch is ok.
4. in a satisfactory or adequate manner adverb
   • They'll do okay on their own.
5. In a satisfactory state or of a satisfactory quality. ADJECTIVE
   • I'll check that the car's 'ok'; that noise from the engine doesn't sound good!
6. to give sanction to verb
   • I oked the resolution.

Synonyms:

• Acceptable
• Adequate
• all right
• fine
• Good
• hunky-dory
• sanction
• Satisfactory
• Very good
• Very well