The Collaborative International Dictionary of English v.0.48:

Overlie \O`ver*lie"\, v. t. [imp. Overlay; p. p. Overlain;
   p. pr. & vb. n. Overlying.]
   To lie over or upon; specifically, to suffocate by lying
   upon; as, to overlie an infant. --Quain.
   [1913 Webster]

         A woman by negligence overlieth her child in her
         sleeping.                                --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Overlying \O`ver*ly"ing\, a.
   Lying over or upon something; as, overlying rocks.
   [1913 Webster]

WordNet (r) 3.0 (2006):

overlying
    adj 1: placed on or over something else; "an overlying image"
           [syn: overlying, superimposed]