means To hold onto something, retain possession of it, or maintain it over time — whether an object, a promise, or a person.

from From Old English 'cepan,' meaning to seize, hold, or observe — and oddly, its earliest senses leaned toward watching and heeding before settling into 'holding onto.' The 'castle keep' (the stronghold's innermost tower) comes from this same family, named because it's the part you hold when all else falls. Its deeper roots are murky; etymologists honestly admit the pre-English ancestry is uncertain.