An Etymological Dictionary of Astronomy and Astrophysics

1. A body or object having → three  → dimensions (length, breadth, and thickness). Of or pertaining to bodies or figures of three dimensions.
   

2. One of the four main → states of → matter, in which the substance molecules vibrate about fixed positions. Unlike a gas or liquid, a solid has a fixed shape, and unlike a gas, a solid has a fixed volume.
   

3. Without holes, free from cavities, not hollow.
   

4. Dense, thick, or heavy in nature or appearance.
   

5. Reliable; that can be depended upon.

Etymology (EN): M.E., from O.Fr. solide “firm, dense, compact,” from L. solidus “firm, whole, entire,” from PIE base *sol- “whole;” cf. Mod.Pers. har “every, all, each, any;” O.Pers. haruva- “whole, all together;” Av. hauruua- “whole, at all, undamaged;” Skt. sárva- “whole, all, every, undivided;” Gk. holos “whole, complete;” L. salvus “whole, safe, healthy,” sollus “whole, entire, unbroken.”

Etymology (PE): Dafzé, from dafzak “big, gross, thick, hard” (Dehxodâ), variant dabz “thick, coarse,” → concentrated; cf. Ossetic baezgin “thick, dense;” Shughni divask, Oroshori devaskak “calf of the leg;” Khotanese baysga- “thick, deep, many, large;” Sogd. δβânz “wide, coarse;” Av. bəzuuant- “thick, dense,” bazah- “thickness;” Proto-Ir. *(d)banz- “to be(come) thick, dense;” cf. Gk. pakhos “thickness, coarseness;” Latvian biezs “thick” (Cheung 2007).