'twas /twoz, twəz/ (archaic or dialect) a contraction of it was

• ballpeen hammer
• ballpeen hammers
• ball-player
• ball-players
• ballpoint
• ballpoint pen
• ballpoint pens
• ballpoints
• ball-proof
• ball rolling
• ballroom
• ballroom dancing
• ballrooms
• balls
• balls-aching
• ballsed-up
• ballsier
• ballsiest
• ballsiness
• ballsinesses
• balls-out
• balls up
• balls-up
• ballsy
• ball up