Disclosed are systems, methods, circuits and associated computer 
executable code for 
deep learning based 
natural language understanding, wherein training of one or more neural networks, includes: producing character strings inputs ‘
noise’ on a per-character basis, and introducing the produced ‘
noise’ into 
machine training character strings inputs fed to a ‘word tokenization and spelling correction language-model’, to generate spell corrected word sets outputs; feeding 
machine training word sets inputs, including one or more ‘right’ examples of correctly semantically-tagged word sets, to a ‘word 
semantics derivation model’, to generate semantically tagged sentences outputs. Upon models reaching a training ‘
steady state’, the ‘word tokenization and spelling correction language-model’ is fed with input character strings representing ‘real’ linguistic user inputs, generating word sets outputs that are fed as inputs to the word 
semantics derivation model for generating semantically tagged sentences outputs.