Memoriter is an adjective that means memorized by heart.
Our word of the day has the same Latin origin of words like ‘memory’ and ‘memoir.’ To commit something to your memory is to commit it memoriter. Here’s an example of memoriter in use:
That poem has remained in my head since the sixth grade when I had to learn it memoriter. Although I still have it memorized, I haven’t had a need to recite it a single time.