WordNet (r) 3.0 (2006):

cling to
    v 1: hold firmly, usually with one's hands; "She clutched my arm
         when she got scared" [syn: cling to, hold close, hold
         tight, clutch]

Moby Thesaurus II by Grady Ward, 1.0:

78 Moby Thesaurus words for "cling to":
   adhere, adhere to, agglomerate, around, bear, bite, bosom, bunch,
   cherish, clasp, cleave, cleave to, clench, clinch, cling, clip,
   clot, cluster, clutch, coagulate, cohere, congeal, conglomerate,
   embosom, embrace, entertain, follow close upon, fondle, foster,
   freeze to, go with, grapple, grasp, grip, gripe, grow together,
   hang about, hang on, hang on to, hang together, harbor, have,
   have and hold, hold, hold fast, hold on, hold on to, hold tight,
   hold together, hover over, huddle, hug, hug the shore, keep,
   keep close to, keep hold of, lie by, march with, mass,
   never let go, nip, nurse, nurture, persist, set, solidify,
   stand by, stay, stay inshore, stay near, stay put, stick, stick to,
   stick together, tailgate, take hold of, treasure, treasure up