number one—
1. (attrib.) first-rate; principal:
- One small folded letter on blue paper bearing a 12-pence stamp will be the number one feature.
2. head of an organization, etc.:
- Gorbachev’s aim was to integrate farm production and food processing. Now, as number one, he could impose his own plan.
3. (coll.) oneself or one’s own interests:
- A significant number of students care about social problems and not just about “number one.”
4. (euph.) is used of the act of urination:
- This little ginger [kitten] is going to do a number one if we’re not careful.
number ones —(coll.) one’s best clothes or uniform:
- Hughes unpacked his kit to find his number ones badly crushed, and cursing, he went in search of an iron.