The New English-Russian Dictionary of Radio-electronics. F.V Lisovsky . 2005.
jamproof — /jam proohf /, adj. built so as to prevent jamming: a jamproof copying machine. [JAM1 + PROOF] * * * … Universalium
jamproof — /jam proohf /, adj. built so as to prevent jamming: a jamproof copying machine. [JAM1 + PROOF] … Useful english dictionary