close support(n = noun.act) - close-in firing by one unit against an enemy engaged by another unit;
is a kind of reenforcement, reinforcement, support

arch support, at close range, bringing close together, child support, close, close at hand, close call, close corporation, close down, close in, close off, close order, close out, close quarters, close set, close shave, close supporting fire, close to, close to the wind, close together, close up, come close, direct support, draw close, financial support, hold close, integrated logistic support, inter-service support, interagency support, interdepartmental support, international logistic support, life support, logistic support, moral support, office of intelligence support, price support, support, support column, support hose, support level, support payment, support stocking, support system