"first" not really meaning the ordinal first [closed]

FIRST has many definitions, including:

• before any other in time, order, or importance
• before doing other things

alternatively:

• in preference to something else : SOONER

I am seeking use examples of the last two definitions -- "first" as a relative term, rather than THE ordinal first

"Head-first" is the best example I can provide. Dive into a pool head-first, and actually your hands will precede the head, so the head is technically not "the first." It's used as a relative term (head-first vs feet-first), not a literal term where your head will be the first body part to contact the water .

Another (weaker) example might be asking someone if they floss first or brush first? Or perhaps at a restaurant, while ordering, the waiter might ask "should I bring the soup first?" (as opposed to with your entree) although you've already been served drinks and some bread.

Thank you for your responses.

definition

An example may be First Among Equals Which has been applied to the British Prime Minister. The Wikipedia article under the link has a number of other interesting applications of the same concept including the Archbishop of Canterbury.

It also contains the useful definition

Bearing higher status and various additional powers while remaining still merely equal to their peers in important senses.