from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. Convert a sentence or a part of it into a theme; modify a verb form by adding a thematic vowel.
- v. Make thematic; organize in themes.
- v. Bring attention to a topic, e.g. by discussing it constructively.
From the stem of Ancient Greek θέμα ("theme") + -ise. (Wiktionary)