1580s, in astrology, "first entrance of a house in the calculation of a nativity," from Latin cuspis "point, spear, pointed end, head," which is of unknown origin. Astronomical sense is from 1670s, "point or horn of a crescent." Anatomical sense of "a prominence on the crown of a tooth" is from 1839.
c. 1300 (mid 13c. in surnames), porte, "a gate, an entrance to a place, a portal; the gate of a town or fortress," also in names of specific gates, from Old French porte "gate, entrance," from Latin porta "a city gate, a gate; door, entrance," akin to portus "harbor," from PIE root *per- (2) "to lead, pass over." Old English also had occasional port in this sense, from Latin, but the Middle English word seems to be a new borrowing via French.
The meaning "porthole, an opening in the side of a ship" is attested from mid-14c.; in old warships, an embrasure in the side of the ship through which cannons are pointed. The medical sense of "place where something enters the body" is by 1908 probably short for portal. In computers, "place where signals enter or leave a data-transmission system," by 1979, from earlier use in electronics (1953) for "pair of terminals where a signal enters or leaves a network or device," which also probably is short for portal.
"main part of a church," the middle part, lengthwise, extending typically from the main entrance to the choir or chancel, 1670s, from Medieval Latin navem (nominative navis) "nave of a church," a special use of Latin navis "ship" (from PIE root *nau- "boat"), on some fancied resemblance in shape.
island at the entrance to Manila Bay in the Philippines, fortified 18c. by the Spanish, it was the place where the maritime registrar recorded the particulars of ships entering the bay, hence the name, from Spanish corregidor "chief magistrate of a town," etymologically "correcter," from Latin corrigere "to put straight; to reform" (see correct (v.)).
1520s, "act of making an indirect suggestion;" 1530s, "that which is indirectly suggested," from French insinuation (16c.) or directly from Latin insinuationem (nominative insinuatio) "entrance through a narrow way; an ingratiating oneself," noun of action from past-participle stem of insinuare "creep in, intrude, wind one's way into" (see insinuate).