thou·sandth 
(thouzəndth, -zənth)
(thouzəndth, -zənth)n.
1. The ordinal number matching the number 1,000 in a series.
2. One of 1,000 equal parts.
thousandth adv. & adj.
- perinatology
- perineal
- perinephral
- perinephrial
- perinephric
- perinephrium
- perineum
- perineurial
- perineurium
- period
- periodic
- periodic acid
- periodical
- periodical cicada
- periodically
- periodic attractor
- periodicity
- periodic law
- periodic motion
- periodic sentence
- Periodic Table
- periodontal
- periodontally
- periodontia
- periodontic