The NeoQuenya and NeoSindarin Wiktionary
Based on Qenya word simpa, and assuming that the initial S didn't come from a TH-.
simpa>sempa>semp
peng 'bow (for shooting)' ety/KWIG
Fiona Jallings, a.k.a. 'dreamingfifi' Merin Essi ar Quenteli! - Wordlists - Reconstructed Sindarin