A compound adjective termination, usually equivalent to the simple -ic, as hysteric, hysterical, but often slightly differentiated, as in comic, comic-al, historic, historic-al, politic, politic-al. (noun)
The Century Dictionary (Public Domain)
Use "ical" in a sentence
"Hm. The only action on my part was to confirm in ical that my address belonged to me."
"Also I am a bit nervous to move to ical from Palm, as I have put a lot of data into my Palm over the years."
"Hiveminder has one-way sync with Google Calendar; you subscribe to the ical feed in gCal, and a Hiveminder icon will appear there."