1550s, "to make dense" (a sense now obsolete or rare), from condens-, past-participle stem of Latin condensare "to make dense" (see condense) + -ate (2). Intransitive meaning "to become dense" is from c. 1600.
early 15c., "thicken, make more dense or compact" (implied in condensed), from Old French condenser (14c.) or directly from Latin condensare "to make dense," from assimilated form of com-, here perhaps an intensive prefix (see com-), + densare "make thick," from densus "dense, thick, crowded," a word used of crowds, darkness, clouds, etc. (see dense).
Sense in chemistry and physics, "to reduce to another and denser form" (as a gas or vapor to a liquid) is from 1660s. Intransitive sense "become denser" is from 1650s. Related: Condensed; condensing.
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.
<a href="https://www.etymonline.com/word/condensate">Etymology of condensate by etymonline</a>
Harper, D. (n.d.). Etymology of condensate. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/condensate