conj

• (nonstandard) And.
  "I'm feeling kinda thirsty, which I do have some beer in the fridge."

det

• (interrogative) What, of those mentioned or implied.
  "Which song shall we play?"
• (relative, formal outside certain phrases) Designates the one(s) previously mentioned.
  "After glaring upon the smoking philosopher, who took his misfortunes with such positive nonchalance, he growled out an oath in German, which language is particularly adapted for growling in; then, raising his hand, he dealt him a blow on his pipe, which sent it, like a rocket, into the midst of the players."

pron

• (interrogative) What one or ones (of those mentioned or implied).
  "Which is which?"
• (not in common use) The/Any ones that; whichever.
  "Please take which you please."
• (relative) In a non-restrictive relative clause, referring to something previously mentioned.
  "I dropped a saucepan, which knocked over the eggs, which went all over the kitchen floor."
• (relative) In a non-restrictive relative clause, referring to something previously mentioned.
  "She had a young child, which cried incessantly."