›the number of products or services that a company sells compared to the number that other companies sell: lose/gain/increase market shareThe company has increased its market share.maintain/regain market shareOur competitor is slashing prices right now in an attempt to regain market share.boost/build/grow market shareOur top strategic objective is to grow market share.market share dropped/fell/roseIts US market share fell to 45% from 50%.