Synonyms of the word 
UNSCALABLE → UNCLIMBABLE
unscalable
- adj. Not scalable, that cannot be climbed.
- adj. Not scalable, that cannot be changed in scale.
unclimbable
- adj. Not able to be climbed.
If you are interested in words, visit the following sites :
- wiktionary.org/unscalable For complete definition of a word
- 1word.ws/unscalable to play with words, suffixs, prefixs, etc.