From The Collaborative International Dictionary of English v.0.48 :
liaise \li*aise"\ (l[=e]*[=a]z"), v. i. [By back-formation from
liaison.]
1. To form or maintain a liaison[3].
[1913 Webster]
2. To act as a liaison[4].
[PJC]
From WordNet (r) 3.0 (2006) :
liaise
v 1: act between parties with a view to reconciling differences;
"He interceded in the family dispute"; "He mediated a
settlement" [syn: intercede, mediate, intermediate,
liaise, arbitrate]