IPA: //əˈsɛn.teɪ.ʃən//
KK: /æˈsɛnˌteɪʃən/
The act of agreeing or giving approval, often in a way that seems insincere or overly eager.
His assentation to the proposal seemed forced and lacking genuine enthusiasm.
Assentation is formed from "ad-" (meaning to) and "sentire" (meaning to feel or think). The word describes the act of agreeing or expressing approval, as it involves a feeling or thought directed towards agreement.
Think of 'feeling' or 'thinking' ('sentire') towards something, which helps you remember that 'assentation' means expressing agreement.