Is it correct to translate 'parayana' as 'the other shore'? Or is there another and better synonym ?
A recurrent image in [Pali Canon] is of life as a raging flood — a flood of birth, aging, and death; sorrow and lamentation; stress and suffering. The purpose of spiritual practice is to find a way across the flood to the safety of the far shore [parayana].
Parāyana, (Parāyaṇa) (nt.) (fr. parā+i, cp. Vedic parāyaṇa highest instance, also BSk. parāyaṇa e.g. Divy 57, 327) 1. (n.) final end, i.e. support, rest, relief S. I, 38; A. I, 155, 156 (tāṇa lena dīpa etc.); J. V, 501=VI, 375 (dīpañ ca p.).—2. (adj.—°) (a) going through to, ending in, aiming at, given to, attached to, having one’s end or goal in; also: finding one’s support in (as daṇḍa° leaning on a stick M. I, 88; A. I, 138), in foll. phrases prevalent: Amata° S. V, 217 sq.; tama° Pug. 51; Nibbāna° S. IV, 373; V, 218; brahmacariya° S. I, 234; Maccu° S. V, 217; sambodhi° D. I, 156; II, 155; Pug. 16. Cp. also Sn. 1114 (tap°=tad°, see Nd2 411); Miln. 148 (ekantasoka°); DhA. I, 28 (rodana, i.e. constantly weeping). ‹-› (b) destined to, having one’s next birth in. , e.g. Avīci° J. III, 454; IV, 159; duggati° PvA. 32; devaloka° J. I, 218; brahmaloka° J. III, 396; Miln. 234; sagga° J. VI, 329; PvA. 42, 160; sugati° PvA. 89 similarly nīlamañca° Pv. II, 25. See also pārāyana.
Pārāyana, (nt.) (late Sk. pārāyaṇa, the metric form of parāyana) the highest (farthest) point, final aim, chief object, ideal; title of the last Vagga of the Sutta Nipāta A. III, 401; Sn. 1130; Nd2 438; SnA 163, 370, 604. > parāyaṇa : (nt.) support; rest; relief; the final end (in cpds.) aiming at; ending in; destined to; finding one's support in.
pārāyana : (nt.) final aim; chief object.
It seems to me parayana has a connotation of "the ultimate". I guess you could also call it "completion".