1. (

• strengthening

) becoming stronger ;

2. (

• strengthening

) the act of increasing the strength of something ;

1. (

• strengthen ,
• beef_up ,
• fortify ,

) make strong or stronger; "This exercise will strengthen your upper body"; "strengthen the relations between the two countries" ;

2. (

• strengthen

) gain strength; "His body strengthened" ;

3. (

• tone ,
• tone_up ,
• strengthen

) give a healthy elasticity to; "Let's tone our muscles" ;