top·ic 
(tŏpĭk)
(tŏpĭk)n.
1. The subject of a speech, essay, thesis, or discourse.
2. A subject of discussion or conversation.
3. A subdivision of a theme, thesis, or outline. See Synonyms at subject.
4. Linguistics A word or phrase in a sentence, usually providing information from previous discourse or shared knowledge, that the rest of the sentence elaborates or comments on. Also called theme.
[Obsolete topic, rhetorical argument, sing. of Topics, title of a work by Aristotle, from Latin Topica, from Greek Topika, commonplaces, from neuter pl. of topikos, of a place, from topos, place.]
- carbon-neutral
- carbon-nitrogen-oxygen cycle
- carbonous
- carbon paper
- carbon process
- carbon star
- carbon tetrachloride
- carbonyl
- carbonylic
- carborane
- Carborundum
- carboxy-
- carboxyhemoglobin
- carboxyl
- carboxylase
- carboxylate
- carboxylation
- carboxylic
- carboxylic acid
- carboxymethylcellulose
- carboxypeptidase
- carboy
- carbuncle
- carbuncled
- carbuncular