Definition of "number two"

number two

noun
countable and uncountable, plural number twos
1. (euphemistic, usually childish) Feces; the act of defecation.
  Quotations
  He might have got up, without the bell's sounding, to do his number one, or number two, in his great big white chamber-pot.
  1953, Samuel Beckett, Watt, Olympia Press
2. (nautical, slang) A first mate.
3. A primary assistant; vice-leader.
  Quotations
  We were meeting in the Oval Office and I saw the morning news report and I just happened casually to mention to George I says- 'Well I'll betcha that President Johnson is gonna be real pleased when he finds that now they are calling me the number one bomber.' And George Christian said 'Oh don't be too sure.' He says, 'You know LBJ- he never likes to be number two.'
  1977, Nixon interviews, spoken by Richard Nixon
4. (cricket) The batsman who opens alongside the number one, but does not face the first delivery.
5. (theater) A somewhat small town, between a number one and a number three, where the success of a theatrical performance is unlikely to be very great.
6. A pencil with hardness level 2.
  Quotations
  They say you should be able to slip a pencil under your boob and if it doesn’t fall out, you’re too saggy. Shit, I could stick a whole box of number twos under these girls and keep them there until next semester.
  2012, Sandra Kring, A Life of Bright Ideas, Bantam Books, page 287
  I reach into my bag, pull out my pencil case, and offer Jason one of my fully sharpened number twos.
  2012, Lauren Morrill, Meant to Be, Delacorte Press, page 108
  “I’ll need pencils, preferably number twos,” I told Miss Rose, who, for some reason, had not budged.
  2015, Sheila Turnage, “Friday Night Miracle”, in The Odds of Getting Even, Kathy Dawson Books, page 234
7. (Philippines) mistress (the other woman in an extramarital relationship, generally including sexual relations)