The Collaborative International Dictionary of English v.0.48:
Pregnant \Preg"nant\, a. [L. praegnans, -antis; prae before +
genere, gignere, to beget: cf. F. pr['e]gnant. See Gender,
1. Being with young, as a female; having conceived; great
with young; breeding; teeming; gravid; preparing to bring
2. Heavy with important contents, significance, or issue;
full of consequence or results; weighty; as, pregnant
replies. " A pregnant argument." --Prynne. " A pregnant
brevity." --E. Everett.
3. Full of promise; abounding in ability, resources, etc.;
as, a pregnant youth. [Obs.] --Evelyn.
Wherein the pregnant enemy does much. --Shak.
Pregnant construction (Rhet.), one in which more is implied
than is said; as, the beasts trembled forth from their
dens, that is, came forth trembling with fright.