This definition comes from the technical glossary.
A Bitcoin payment address comprising a hashed script, allowing the spender to create a standard pubkey script that Pays To Script Hash (P2SH). The script can be almost any valid pubkey script.
P2PK output (an output paying a public key directly)
P2PKH address, P2PKH output (an address comprising a hashed pubkey, and its corresponding output)
P2SH multisig (a particular instance of P2SH where the script uses a multisig opcode)
P2SH — Developer Guide
BIP16: pay to script hash — Bitcoin Improvement Proposals
P2SH — Bitcoin Wiki