impregnate (v.)

["convincing, weighty, pithy, full of meaning"] late 14c., "cogent, convincing, compelling" (of evidence, an argument, etc.); c. 1400 as "full of meaning;" from Old French preignant "pregnant, pithy, ready capable," which is probably from Latin praegnans "with child, pregnant, full" and thus the same word as pregnant (adj.1).

All uses seem to be derivable from the sense of "with child." But in some sources this English pregnant has been referred to French prenant, present participle of prendre "to take," or to the French present participle of preindre "press, squeeze, stamp, crush," from earlier priembre, from Latin premere "to press, hold fast, cover, crowd, compress." The two English adjectives are so confused as to be practically one word, if they were not always so.

late 14c., "making or becoming pregnant," from Old French impregnacion or directly from Late Latin impregnationem (nominative impregnatio), noun of action from past participle stem of impraegnare "to impregnate" (see impregnate).