Concept: complementizer

Definition

A complementizer is a °marker that indicates that the °clause on which it occurs is a °complement clause.

Comments

Note that there is no corresponding verb ("to complementize").

Croft's comparative concept
complementizer (STR):

complementizer (STR) = a morpheme that overtly expresses the semantic relation in a complement clause construction. Example: in She thought that he was tired, that is the complementizer. A complement clause construction with a complementizer is an example of syndetic subordination. If the morpheme is affixed to a predicate, it is not a complementizer but an overt marker of deranked status. (Section 18.3.1)

Wikipedia
complementizer
SIL Glossary
complementizer
Quotation
"Complementizer: A word from a small class of grammatical items which introduce a clause, such as English that or whether. May indicate the tense or finiteness of the clause. In head-final languages, a complementizer often follows the clause." (Tallerman 2011: 2092)
Sources
Tallerman 2011