| firstborn |
born before any other child or offspring of a parent or parents. [2 definitions] |
| first cause |
a primary or original source, independent of, and not caused by, anything else. [2 definitions] |
| first class |
the best, finest, or highest in quality, class, grade, or rank. [3 definitions] |
| first-class |
of the highest in quality, rank, or grade; foremost; best. [4 definitions] |
| first cousin |
the offspring of one's uncle or aunt. |
| first-degree |
of or concerning the lowest or first level in a series of levels or intensities. [2 definitions] |
| first-degree burn |
the level of burn that produces pain, heat, and reddening of the skin but no blistering or charring. |
| first-degree murder |
a premeditated murder, carried out with deliberate intention to kill. |
| first dibs |
(informal) the first claim or right to something. |
| first finger |
the finger next to the thumb; forefinger; index finger. |
| first floor |
in American English, the ground floor. In British English, the floor above the ground floor. |
| first-generation |
denoting a person who is a naturalized citizen of a nation, having immigrated from another country. [2 definitions] |
| firsthand |
from the original source; directly. [2 definitions] |
| first lady |
(often cap.) the wife or official hostess of a chief executive, esp. of the U.S. president. [2 definitions] |
| first lieutenant |
a commissioned officer of the U.S. Army, Air Force, or Marines, ranking below a captain and above a second lieutenant. |
| first light |
the beginning of daylight; daybreak; dawn. |
| firstling |
the first of its kind, such as the first fruits of a season. [2 definitions] |
| firstly |
to start with; first. |
| first mate |
the officer of a merchant ship second in rank to the captain; mate. |
| first mortgage |
a primary lien against a piece of property that takes precedence in case of default over all other mortgages or liens except those given priority by law, such as real estate taxes. |
| first night |
the opening performance of a play, opera, movie, or the like, or the night on which this occurs. |