Ungained

Men prize the thing ungained more than it is;

Source: wiktionary

The streams run on, in bold, malicious haste, His lip can touch the fruit, but cannot taste; In vain he struggles from his chain to burst The stream, the fruit's ungained—unquenched his thirst!

Source: wiktionary

To refer to something ungained seems impossible in an ordinary way, but we can simulate the time evolution by the method called "generate-and-search".

Source: wiktionary

ungained advantage

Source: wiktionary