indicate

Etymology

From Latin indicatus, past participle of indicāre (“to point out, indicate”), from in (“in, to”) + dicāre (“to declare, originally to point”); see diction. Compare index.

verb

1. To point out; to discover; to direct to a knowledge of; to show; to make known.
   The guard blew his whistle to indicate imminent departure.
   Many genes with reproductive roles also have antibacterial and immune functions, which indicate that the threat of microbial attack on the sperm or egg may be a major influence on rapid evolution during reproduction. 2013 May-June, Katrina G. Claw, “Rapid Evolution in Eggs and Sperm”, in American Scientist, volume 101, number 3
2. To show or manifest by symptoms; to point to as the proper remedies.
   Great prostration of strength indicates the use of stimulants.
3. To signal in a vehicle the desire to turn right or left.
4. To investigate the condition or power of, as of steam engine, by means of an indicator.
   To a person who is familiar with the use of an indicator, whether it be of one make or another, it is needless to give instructions as to how an engine should be indicated,[…]. 1903, “How to indicate an engine”, in The Star Improved Steam Engine Indicator, page 64
   I found it fully as easy to indicate an engine at a speed of 320 to 340 revolutions as at 80. 1905, Power, volume 25, page 448
   An indicator will give the working of these valves at all times and soon return its cost in higher engine efficiency. The day has passed when it was only the expert who could indicate an engine or afford to own an indicator. 1905, Central Station, volume 5, page 76