Often; fairly frequently — used in casual speech to indicate things happening repeatedly or repeatedly over time.
彼はちょくちょく海外出張に行く。
He goes on business trips abroad quite often.
最近ちょくちょく雨が降るので洗濯物が乾かない。
Lately it rains off and on, so the laundry won't dry.
ちょくちょく店に顔を出してくれる常連客がいる。
There are regular customers who drop by the shop from time to time.