An Etymological Dictionary of the German Language/Kleister
Kleister, m. and f., ‘paste,’ from the equiv. MidHG. klîster, m., with the equiv. variant klënster based on the vb. klënen; OHG. chlîstar and Goth. *kleistra- are wanting; stra is a suffix, as in Laster; the stem klî is the root klî, by gradation klai, ‘to cleave (to)’ (discussed under Klei and klein), which forms a vb. only in OHG., but it passes at the same time into the e-class, chlënan, ‘to cleave (to), smear,’ for kli-na-n, with na as a suffix of the pres., as in Lat. and Gr. (sper-ne-re, li-ne-re, δάκνειν, &c.); comp. MidHG. klënen, vb., Ic. klína, ‘to smear,’ klíningr, ‘bread and butter,’ klístra, ‘to paste.’