indeterminate

not precisely determined or established; not fixed or known in advance; "of indeterminate age"; "a zillion is a large indeterminate number"; "an indeterminate point of law"; "the influence of environment is indeterminate"; "an indeterminate future"

भीतर के दरवाज़े की कुंडी पर हाथ धरे वह अनिश्चित-सा खडा रहा-अपनी आँखों पर विश्वास करना उसे असम्भव-सा जान पड़ा।

The colour of the curtain was indeterminate half way between grey and brown.