Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
praepărātĭo, ōnis, f. [praeparo]. 
- I.  A getting or making ready, a preparing, preparation (class.): priusquam aggrediare, adhibenda est praeparatio diligens, Cic. Off. 1, 21, 73: provisio animi et praeparatio ad minuendum dolorem, id. Tusc. 3, 14, 30: belli, Vell. 1, 12, 6: futurae impensae, Front. Aquaed. 124: cordis, Vulg. Psa. 9, 17 (37): pugnae, id. Judith, 4, 4.
 
- II.  Rhet., a preparation of the hearers for what is to follow,  =  προπαρασκευή, Quint. 7, 10, 12; 4, 2, 55; 9, 2, 17.