Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
culcĭta (in MSS. also culcĭtra), ae, f. [etym. dub.; acc. to Varr. L. L. 5, § 167 Müll.; Paul. ex Fest. p. 50, 8, from calco], a sack filled with feathers, wool, hair, etc., for lying upon, warming, etc.; a bed, cushion, mattress, pillow, Cato, R. R. 10 fin.; 11 fin.; Varr. ap. Non. p. 86, 5 sq.; Cic. Tusc. 3, 19, 46; Sen. Ep. 87, 2; 108, 23; Suet. Tib. 54 al.
Of a little cushion or patch for the eye, Plaut. Mil. 4, 4, 42.
Of a resting-place in a conservatory of birds, Varr. R. R. 3, 5, 14.
In the lang. of comedy: gladium faciam culcitam Eumque incumbam, I will make the sword my couch, i. e. I will make away with myself, Plaut. Cas. 2, 4, 28.