noun which may take the genitive case particle 'no'
under the influence of; influenced by
Used as a noun followed by の to modify another noun, indicating that something is under the influence or effect of something else. Often appears in formal or written contexts.
He caused an accident while under the influence of alcohol.
The policy is under strong political influence.
Compound of 影響 (influence) and 下 (under). The reading is the standard on'yomi combination.