There are 62 words that start with 'slip'.
Note: These 62 words that start with 'slip' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with slipp, slips, slipc, slipf, slipo, slipw, slipe, slipd, slipk, slipu, slipi, slipl, slipt.