| thio- or (before a vowel) thi- | |
| —combining form | |
| indicating that a chemical compound contains sulphur, esp denoting that a compound is derived from a specified compound by the replacement of an oxygen atom with a sulphur atom: thiol; thiosulphate | |
| [from Greek theion sulphur] | |
| thi- or (before a vowel) thi- | |
| —combining form | |
| [from Greek theion sulphur] | |
thi- pref.
Variant of thio-.
| thio- or thi-
A prefix that means "containing sulfur," used especially of a compound in which an oxygen atom has been replaced by a sulfur atom, as in thiourea. |