| semirigid | (adj) having a form maintained by a rigid internal structure as well as by internal gas pressure |
| semirigid | (adj) not fully rigid |
| Semiradial | a. Half radial. [ Webster 1913 Suppl. ] |
| Semiradial engine | . (Mach.) See Radial engine, above. [ Webster 1913 Suppl. ] |
| Semirecondite | a. (Zool.) Half hidden or half covered; said of the head of an insect when half covered by the shield of the thorax. [ 1913 Webster ] |
| Semiring | n. (Anat.) One of the incomplete rings of the upper part of the bronchial tubes of most birds. The semirings form an essential part of the syrinx, or musical organ, of singing birds. [ 1913 Webster ] |