Quick definitions from WordNet (pattypan squash)
▸ noun: round greenish-white squash having one face flattened with a scalloped edge
▸ noun: squash plant having flattened round fruit with a scalloped edge; usually greenish white
▸ noun: round greenish-white squash having one face flattened with a scalloped edge
▸ noun: squash plant having flattened round fruit with a scalloped edge; usually greenish white