One (Swedish House Mafia song) definition

(1) Being a single entity made by combining separate components

"Three chemicals combining into one solution"

(2) Used of a single unit or thing; not two or more

"`ane' is Scottish"

(3) A single person or thing

"He is the best one"

"This is the one I ordered"

(4) The smallest whole number or a numeral representing this number

"He has the one but will need a two and three to go with it"

"They had lunch at one"