You use at first when you are talking about what happens in the early stages of an event or experience, or just after something else has happened, in contrast to what happens later .
First aid is simple medical treatment given as soon as possible to a person who is injured or who suddenly becomes ill .
You use first off to introduce the first of a number of things that you want to say .
designating or of:
If you say that someone or something comes first for a particular person, you mean they treat or consider that person or thing as more important than anything else.
someone in an organization who has been trained to give immediate medical help in an emergency
the base that a runner must reach safely to score a hit, and the first of the three bases the runner must reach safely on the way to home plate in order to score a run
the first killing or wounding in a fight or war
Someone's first born is their first child.
a source or cause of something
If you describe something or someone as first-class, you mean that they are extremely good and of the highest quality.
the first play of the set of four downs allowed to the offensive team
Something that is the first ever one of its kind has never happened before.
the fleet of convict ships that arrived at Port Jackson in 1788
The first floor of a building is the floor immediately above the one at ground level.
the first person to enter a household in the New Year . By Hogmanay tradition a dark-haired man who crosses the threshold at midnight brings good luck
the first class that children go into at school
the first school year after kindergarten when children are six or seven years old
First hand information or experience is gained or learned directly, rather than from other people or from books.
The First Lady in a country or state is the wife of the president or state governor, or a woman who performs the official duties normally performed by the wife.
First light is the time in the early morning when light first appears and before the sun rises .
acting or used as a first resort
an officer second in command to the captain of a merchant ship
the Aristotelian conception of God as the unmoved mover of everything else
Your first name is the first of the names that were given to you when you were born. You can also refer to all of your names except your surname as your first names .
→ the first-named
The first night of a show, play, or performance is the first public performance of it.
quantifying only over individuals and not over predicates or clauses : first-order predicate calculus studies the logical properties of such quantification
the first of two military bugle calls ordering or giving notice of the time to retire for the night . The second is called last post
If you say that something or someone is first-rate, you mean that they are extremely good and of the highest quality.
the Holy Roman Empire ( First Reich )
→ the First State
If you do something first thing, you do it at the beginning of the day, before you do anything else. If you do it last thing, you do it at the end of the day, before you go to bed or go to sleep .
A first-timer is someone who does something for the first time.
the finest quality of diamond or other precious stone
The most prosperous and industrialized parts of the world are sometimes referred to as the First World . Compare → Third World .
the first year when someone is at university or college
If you move head-first in a particular direction, your head is the part of your body that is furthest forward as you are moving.
being between sixty and sixty-two in numbering or counting order, position, time, etc: often written 61st
a first-class honours degree in two subjects
the infielder who plays near first base and usually covers first base, esp. on ground balls
→ the first couple
Someone's first cousin is the same as their → cousin . Compare → second cousin .
People who have gained a higher qualification after completing a basic university degree such as a BA or a BSc refer to that basic degree as their first degree .
one of the first printed copies of a book or newspaper
the period of imperial rule in France (1804–14) under Napoleon Bonaparte
the first of the three estates of the realm, such as the Lords Spiritual in England or the clergy in France until the revolution
a family considered to have prestige because of descent, social status, etc.
the finger next to the thumb ; index finger