soften up

verb

1. to make or become soft

2. (tr) to weaken (an enemy's defences) by shelling, bombing, etc

3. (tr) to weaken the resistance of (a person) by persuasive talk, advances, etc

Idioms and Phrases

Reduce resistance, as in His sales motto was: a fine lunch and a few drinks often will soften up a prospective customer. This expression transfers lessening of physical hardness to lessening mental resistance. It was first used, however, in World War II, where it meant “reduce the enemy's defenses by preliminary bombing.” [c. 1940]

Related Words

• dominate 
• impress 
• inspire 
• overrule 
• persuade