When you want to say that something is enough or good enough for a particular need, use the adjective adequate. You might have an adequate amount of flour for a batch of pancakes, but not a lot extra.
Adequate can also describe something that is acceptable or satisfactory, but not any better than that. You might say that a student's grades are adequate but need improvement. This word is from Latin adaequāre"to make equal," from the prefix ad- plus aequare "to equal."