I. ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: curb (II) (rim) + stone
: a stone set along a margin as a limit and protection — called also edgestone
II. adjective
1. : operating in a curb market or on the street without maintaining an office
a curbstone broker
2. : based on chance impression, random observation, or hunches
curbstone advice
curbstone opinion
: not having the benefit of training or experience : amateurish
a curbstone engineer
a curbstone commentator