capacitate (v.)

early 15c., capacite, "ability to contain; size, extent;" also "ability" in a legal, moral, or intellectual sense, from Old French capacité "ability to hold" (15c.), from Latin capacitatem (nominative capacitas) "breadth, capacity, capability of holding much," noun of state from capax (genitive capacis) "able to hold much," from capere "to take" (from PIE root *kap- "to grasp").

The sense of "power to store electricity" is from 1777; the industrial sense of "ability to produce" is from 1931. The meaning "power of containing a certain quantity" is from 1885, hence "largest audience a place can hold" (1908).

verbal suffix for Latin verbs in -are, identical with -ate (1). Old English commonly made verbs from adjectives by adding a verbal ending to the word (such as gnornian "be sad, mourn," gnorn "sad, depressed"), but as the inflections wore off English words in late Old and early Middle English, there came to be no difference between the adjective and the verb in dry, empty, warm, etc. Thus accustomed to the identity of adjectival and verbal forms of a word, the English, when they began to expand their Latin-based vocabulary after c. 1500, simply made verbs from Latin past-participial adjectives without changing their form (such as aggravate, substantiate) and it became the custom that Latin verbs were Englished from their past participle stems.