Green’s Dictionary of Slang

1. to chat.

1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 49: Chirrup ? said of birds; and a man that sits and quaffs and talks gaily, is said to chirrup ? probably from the ‘cheer ups’ he has taken.
1833		‘Life in St Giles’s’ in Corinthian in Spedding & Watt (eds) Bawdy Songbooks (2011) IV 41: Bless your eyes and limbs, lay out a mag with poor chirruping Joe.
1893		P.H. Emerson Signor Lippo 104: Blower had just [...] settled himself down in his chair to smoke, and have a chirrup with Bottle Nose.

2. of a man, to call after girls and women in the street.

1882		Bristol Magpie 24 Aug. 1/2: He would keep ahead of the fair one, occasionally glancing back, until he reached the corner of the street, where he would take his stand, stare impertinently as she passed, and ‘chirrup’ after her when she had gone.
1882		Bristol Magpie 16 Nov. 10/1: We Hear [...] That there is not so much chirruping in St. Mark’s Road as formerly, the birds being scared.

3. to cheer or boo a music-hall turn [the response varies as to whether or not the singer has tipped the gallery].

1888		J. Payn in Illus. London News 17 Mar. 268: Did poet or painter, for example, ever have a ‘chirruper’ in their employment? The players and singers in music-halls cannot, it seems, do without him.
1888		police court report 6 Mar. in Ware (1909) 73/1: Pike, the stage-doorkeeper at the Canterbury, proved seeing the prisoner [...] carrying on the system of obtaining money for what in the slang of the gang is called ‘chirruping.’.