Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. collectus (conl-), a, um, Part. and P. a., from 1. colligo.
2. collectus (conl-), ūs, m. [1. colligo], a collection: aquae, Lucr. 4, 414 Lachm. N. cr.; cf.: aquae pluvialis, Front. Limit. p. 43 Goes.: lapidum, Lucr. 3, 198: auri et argenti, Tert. Anim. 37.