ˈ ̷ ̷ ̷ ̷ˌsti(ə)r noun
also iso·ster -ˌste(ə)r
( -s )
Etymology: is- + -stere, -ster (from Greek stereos solid) — more at stare
1. : a line on a map or chart connecting points of equal atmospheric density
2.
[probably back-formation from isosteric ]
: one of two or more substances related by isosterism