Synonyms for call-in

Most common

1. Call on — to pay a short visit

2. Re-call

re-call, call, phone in, visit, summon

Other

ring in

v. 1
To pay a short visit.
Near-synonym: call on (transitive)
v. 2
To communicate with a base etc, by telephone.
I was too unwell to work yesterday so I called in sick.
adj. 1
In which members of the public telephone the studio and talk live to the presenter.

The small number after each word is its number of syllables (visit² = 2 syllables).