1. 
[syn: comfort, comfortableness]
2.  a feeling of being at ease in a relationship; 
The Collaborative International Dictionary of English v.0.48:
Comfortableness \Com"fort*a*ble*ness\, n.
   State of being comfortable.
   [1913 Webster]
WordNet (r) 3.0 (2006):
comfortableness
    n 1: a state of being relaxed and feeling no pain; "he is a man
         who enjoys his comfort"; "she longed for the
         comfortableness of her armchair" [syn: comfort,
         comfortableness] [ant: discomfort, uncomfortableness]
    2: a feeling of being at ease in a relationship