adjective

1. preceding all others in a series; before any other; 1st
2. happening or acting before all others; earliest
3. ranking before all others; foremost in rank, quality, importance, etc.; principal
4. designating the slowest forward gear ratio of a motor vehicle transmission; low ()
5. Music playing or singing the part highest in pitch or the leading part

Etymology: ME < OE fyrst, lit., foremost, superl. of fore, before (see fore), akin to OHG furist, Ger fürst, prince, lit., foremost < IE base *per-, beyond > L prae, before, Gr para, beside, beyond

adverb

1. 1. before any other person or thing; at the beginning
   2. before doing anything else
2. as the first point; to begin with
3. for the first time
4. sooner; preferably

noun

1. the one before the second
2. any person, thing, class, place, etc. that is first
3. the first day of a month
4. the beginning; start
5. a first happening or thing of its kind
6. the best quality of merchandise
7. the winning place in a race or competition
8. the first () gear of a motor vehicle transmission; low ()
9. ☆ Baseball first base
10. Music the highest or leading voice or instrument in an ensemble