if u knwo that cliff is A steep high face of rock, then its easy to remember
ac+cliv+ity....cliv is similar to CLIMB..can relate to the meaning...climbing the steep upslope of a hill
try to look for 'cliff' in this word and cliff means a high, steep face of rock. Also, try to look for elevate (elivity) in this word which also means upslope.
ac+CLIV+ity..cliv= means SLOPE or tendency so an UPWARD SLOPE.
clivus in Latin means slope.
spells like activity,activity to climb on an upward slope..
cleavage men gahrai hai, acclivity men chadhai hai