tril·lionth 
(trĭlyənth)
(trĭlyənth)n.
1. The ordinal number matching the number one trillion in a series.
2. One of a trillion equal parts.
trillionth adv. & adj.
- cross-fertile
- cross-fertilization
- cross-fertilize
- cross-file
- cross-filer
- crossfire
- cross-grained
- cross hair
- crosshair
- crosshatch
- cross-hatching
- crosshead
- cross-index
- crossing
- crossing over
- crossing-over
- cross-legged
- cross-link
- crossly
- cross matching
- cross mind
- cross multiplication
- cross-multiply
- cross-national
- crossness