1. (n.) The act of piercing, or entering\; also, the act of mentally penetrating into, or comprehending, anything difficult.

2. (n.) Acuteness; insight; sharp discoverment; sagacity; as, a person of singular penetration.

access acuity acumen acupunctuation acupuncture acuteness admission apperception astuteness bore boring broach cleverness cogency critical discernment decoction diffusion discernment discrimination drill hole embedment empiercement entrance entree entry farseeingness farsightedness fixing flair foresight foresightedness goring graft grafting imbuement impaction impactment impalement implantation import importation importing impregnation incision incisiveness income incoming infiltration infixion infusion ingoing ingress ingression injection inoculation input inroad insertion insight insinuation instillation instillment intake intelligence interjection interpenetration interpolation introduction introgression intromission intrusion judgment keenness lancing leakage longheadedness longsightedness marination overrunning overspreading overswarming penetrating perception perceptiveness percipience percolation perforation perfusion permeation perspicaciousness perspicacity perspicuity perspicuousness pervasion piercing pricking providence punching puncture puncturing quick-wittedness reception sagaciousness sagacity saturation seepage sensibility sensitivity sentience shrewdness skewering soaking steeping suffusion terebration tessellation transfixation transfixion transforation transfusion transplant transplantation trenchancy trepanning trephining understanding wit