は疎(おろ)かLet alone, Much less, Needless to say, Not to mention, Not only but also

は疎(おろ)か is an expression that works similarly to はもちろん 'of course (A), but (B)' in Japanese. 疎(おろ)か itself is a な-Adjective that means 'negligent', or 'alienation'. However, this use of 疎(おろ)か is not seen much in modern Japanese, and the word will mainly be used in set expressions where it doesn't behave exactly as a な-Adjective usually would. Despite this, the meaning of 'alienation', or 'completely removed from' is kept in はおろか, as it simply means 'completely putting aside (A), (B)'.

Common translations include 'let alone (A), (B)', and 'it's needless to say that (A), when (B)'. (B) and (A) will usually be things that fall into the same category, where (B) is considered the far more obvious of the two. Due to this obviousness, (B) will often be immediately followed by the adverbial particle さえ. This shows that (B) is the noteworthy minimum extent.

Alternatively, さえ may be exchanged with other adverbial particles that fill a similar purpose such a も, すら, or まで. In most cases, は疎(おろ)か sentences tend to have a fairly negative nuance.