Definitions

1. noun

a spiral that is not a complete turn, especially the shape formed by the upper limb of a mollusk, such as a snail or a squid, in the process of crawling or swimming

“The biologist studied the semispiral shells of the snails in the museum’s collection.”

2. adjective

describing or forming a spiral that is not a complete turn

“The semispiral pattern on the fabric caught the designer’s eye and inspired a new collection.”