1.  retiring(s = adj.all) unassuming - not arrogant or presuming; "unassuming to a fault, skeptical about the value of his work"; "a shy retiring girl"

2.  retiring(s = adj.all) past, preceding - of a person who has held and relinquished a position or office; "a retiring member of the board"

3.  retiring(s = adj.all) reticent, self-effacing - reluctant to draw attention to yourself;

1.  Reserved; shy; not forward or obtrusive; as, retiring modesty; retiring manners. [1913 Webster]

2.  Of or pertaining to retirement; causing retirement; suited to, or belonging to, retirement. [1913 Webster]

retiring, adj. shy; fond of seclusion.

Derivative:
retiringly adv.

N  concavity, depression, dip, hollow, hollowness, indentation, intaglio, cavity, dent, dint, dimple, follicle, pit, sinus, alveolus, lacuna, excavation, strip mine, trough, honeycomb, cup, basin, crater, punch bowl, cell, socket, valley, vale, dale, dell, dingle, combe, bottom, slade, strath, glade, grove, glen, cave, cavern, cove, grot, grotto, alcove, cul-de- sac, gully, arch, bay, excavator, sapper, miner, honeycomb (sponge), depressed, alveolate, calathiform, cup-shaped, dishing, favaginous, faveolate, favose, scyphiform, scyphose, concave, hollow, stove in, retiring, retreating, cavernous, porous, infundibul, infundibular, infundibuliform, funnel shaped, bell shaped, campaniform, capsular, vaulted, arched.

N  blueness, blue, garter-blue, watchet, ultramarine, smalt, cobalt, cyanogen, Prussian blue, syenite blue, bice, indigo, zaffer, lapis lazuli, sapphire, turquoise, indicolite, blueness, bluishness, bloom, blue, azure, cerulean, sky-blue, sky-colored, sky-dyed, cerulescent, powder blue, bluish, atmospheric, retiring, cold.