

invert
/ɪnˈvɜːrt/ /ˈɪnvɜːrt/






noun
The base of a tunnel on which the road or railway may be laid and used when construction is through unstable ground. It may be flat or form a continuous curve with the tunnel arch.







noun
A skateboarding trick where the skater grabs the board and plants a hand on the coping so as to balance upside-down on the lip of a ramp.















