IPA: /ˌjuːnɪˈraɪnɪk/
KK: /ˌjunəˈraɪnɪk/
This word describes something that is sincere and straightforward, without any hint of sarcasm or irony.
Her unironic appreciation for the movie surprised everyone, as most people found it cheesy.
Unironic → It is formed from "un-" (meaning not) and "ironic" (from Greek "eironeia", meaning dissimulation or feigned ignorance). The word "unironic" means not characterized by irony, or straightforward in expression.
Think of 'not' ('un-') being added to 'ironic', which helps you remember that 'unironic' means something that is straightforward and sincere.