teneo

Teneo, tenere, tenui, tentum, second conjugation. Physical grip is the base sense, and everything else follows from it: to hold a position against an army, to hold a man to his promise, to hold a course, to hold something in the mind. Memoria tenere is the ordinary way to say "remember", and teneo on its own in dialogue means "I've got it, I understand".

Do not confuse it with habeo. Habeo is possession as a state; teneo is grip, with effort in it. The compounds shift the vowel to -tineo and are everywhere: contineo, retineo, obtineo, pertineo, sustineo, abstineo. From the same root, tenax gives tenacious, tenor is the holding line of a melody and then the drift of an argument, and tenement, tenure and lieutenant all trace back to somebody holding something.