歯芽 is read as しが (shiga) and means tooth germ.
しが
shiga
はごたえ
challenge (e.g. work, book)
しかえいせいし
dental hygienist
しかえいせいしほう
Dental Hygienists Act
しかぎこうし
dental technician
しけいそくめんせっきんおん
alveolar lateral approximant
しかけんしん
dental exam
しかきょうせいがく
orthodontics
はぎりばん
gear cutting machine
はぐきそくめんはじきおん
alveolar lateral flap
きのめ
bud of Japanese pepper tree (Xanthoxylum piperitum)
め
germinal disk (in an egg)
はつが
germination