1) Like some sci-fi boots 2) The antithesis of gravity 
A hypothetical force that acts in a direction opposite to that of normal gravity. More generally, any means of modifying the effects of gravity, through some form of shielding or otherwise. Antigravity, gravity modification, and gravitational anomalies are subjects that have been considered both wi...
See: anti-G. ... (05 Mar 2000) ... 
Type: Term Pronunciation: an′tē-grav′i-tē See: anti-G
the antithesis of gravity; a hypothetical force by which a body of positive mass would repel a body of negative mass. · (not in technical use) a controllable force that can be made to act against the force of gravity.