adjective
dial-in

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APA Style
(not comparable)
When used as an adjective, hyphenated; when used as a verb, unhyphenated (dial up). Use as a synonym for dial-up is proscribed, as dial-up consists of outgoing calls (a network client), not incoming calls (a network server).
dial + in
(third-person singular simple present dials in, present participle dialing in, simple past and past participle dialed in)
- configure, set up, particularly a complex machine with many configuration options (especally knobs and dials).
- join or participate in a conference call.
- Did you dial in to that earnings announcement?
When used as a verb, unhyphenated; when used as an adjective in networking or motorsports, hyphenated (dial-in).
dial + in, from tuning in to a radio frequency by changing the dial.
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APA Style