• 02.036 when Balin, who was always their look-out man, said:
• 06.005 it was Balin doing look-out.
• 06.014 of a look-out man who let people walk right into them
• 09.062 There were people on the look-out on the banks.
• 12.005 the look-out man,
• 13.053 we ought to make for the old look-out post

The noun entry has hyphens in the examples, and the verb entry is a marvelous rabbit-hole of nautical terms!

“look, v.” OED Online, Oxford University Press, June 2017, http://www.oed.com/view/Entry/110130. Accessed 15 September 2017.

“lookout, n.” OED Online, Oxford University Press, June 2017, http://www.oed.com/view/Entry/110143. Accessed 15 September 2017.