[1] : The Collaborative International Dictionary of English v.0.48

yellow \yel"low\, v. t. imp.  p. p. yellowed; p. pr.  vb.
   n. yellowing.
   to make yellow; to cause to have a yellow tinge or color; to
   dye yellow.
   1913 webster
see also:
yellowed yellowing 

[2] : The Collaborative International Dictionary of English v.0.48

yellowing \yel"lowing\, n.
   the act or process of making yellow.
   1913 webster

         softened . . . by the yellowing which time has given.
                                                  --g. eliot.
   1913 webster

Yellowing >> Y Words
Yellowing, definition of term: Yellowing
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