1 : make less fast or intense
2 : make an examination or investigation
3 : verify by consulting a source or authority
4 : slow the growth or development of
5 : put to the test, as for its quality, or give experimental use to
6 : become fractured; break or crack on the surface only
7 : check or regulate (a scientific experiment) by conducting a parallel experiment or comparing with another standard
8 : develop (children's) behavior by instruction and practice; especially to teach self-control
9 : examine carefully for accuracy with the intent of verification
10 : keep tabs on; keep an eye on; keep under surveillance
11 : watch and direct
12 : look at again; examine again