The Collaborative International Dictionary of English v.0.48:
Collodion \Col*lo"di*on\, n. [Gr. ? like glue; ko`lla glue + ?
form. Cf. Colloid.] (Chem.)
A solution of pyroxylin (soluble gun cotton) in ether
containing a varying proportion of alcohol. It is strongly
adhesive, and is used by surgeons as a coating for wounds;
but its chief application is as a vehicle for the sensitive
film in photography.
Collodion process (Photog.), a process in which a film of
sensitized collodion is used in preparing the plate for
taking a picture.
Styptic collodion, collodion containing an astringent, as