collimator

• POS: Noun
• HYPHEN: col=li=ma=tor

CIDE DICTIONARY

collimator, n. 

•  A telescope arranged and used to determine errors of collimation, both vertical and horizontal.  Nichol.  [1913 Webster]
•  A tube having a convex lens at one end and at the other a small opening or slit which is at the principal focus of the lens, used for producing a beam of parallel rays; also, a lens so used.  [1913 Webster]

OXFORD DICTIONARY

collimator, n.
1 a device for producing a parallel beam of rays or radiation.
2 a small fixed telescope used for adjusting the line of sight of an astronomical telescope, etc.