ONlwSG

callan m. [ˈkʰɑɫ̪an], gen. callain -[æɲ], -[ɛɲ], ‘noise, clamour; repeated hammering; constant repetition; continuation, continuity; 

E.g. thug e callan air (Faclan bhon t-Sluagh^˄, s.v. callan: Scalpay) ‘he kept on about it’; cf. tha e air an aon iorram and tha an t-aon iorram air (ibid., s.v. iorram) ‘he keeps on about it’ (see Ó Maolalaigh 2006b, 248–50).

a while’ (AFB^˄) is tentatively derived by McDonald (2009, 368) from ON kall nt. ‘call, cry’; this is on the basis of Craigie’s (1894, 161) derivation of O’Reilly’s (1817 etc.) Ir. callán in the senses ‘shout, noise’ from the same source.

Cf. callán ‘noisy talk’ (Quiggin 1906, 79, §206: Donegal), ‘noise, clamour (of voices)’ (Dinneen 1947).

MacBain (1896; 1911) suggests SG callan and Ir. callán may be based on Eng. call; 

MacBain’s entry reads ‘callan “a noise”, Ir. callán, callóich; from Eng. call?’, but callóich seems to be a typesetting error for callóid, s.v. callaid.

cf. SG calla ‘a call (to a congregation)’ (Faclan bhon t-Sluagh^˄: cò am ministear dhan tug sibh calla?, Lewis [‘which minister did you give a call to?’]).

Derivatives: callanach ‘noisy clamorous’.

Ir. callán and callánach are possibly loans from Scottish Gaelic.