The Collaborative International Dictionary of English v.0.48:

Sentimentalize \Sen`ti*men"tal*ize\, v. t.
   To regard in a sentimental manner; as, to sentimentalize a
   subject.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sentimentalize \Sen`ti*men"tal*ize\, v. i.
   To think or act in a sentimental manner, or like a
   sentimentalist; to affect exquisite sensibility. --C.
   Kingsley.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sentimentalize
    v 1: look at with sentimentality or turn into an object of
         sentiment; "Don't sentimentalize the past events" [syn:
         sentimentalize, sentimentalise]
    2: make (someone or something) sentimental or imbue with
       sentimental qualities; "Too much poetry sentimentalizes the
       mind"; "These experiences have sentimentalized her" [syn:
       sentimentalize, sentimentalise]
    3: act in a sentimental way or indulge in sentimental thoughts
       or expression [syn: sentimentalise, sentimentalize,
       sentimentize, sentimentise]