IPA: /ɒˈstɛnsɪbli/
KK: /ɔˈstɛnsəblɪ/
In a way that appears to be true but may not be; seemingly or apparently.
Ostensibly, he was happy with the decision, but I could tell he was upset.
Ostensibly → It is formed from "ostensibilis" (from Latin, meaning capable of being shown) and the suffix "-ly" (meaning in a manner of). The word "ostensibly" means in a manner that appears to be true or is stated to be true, but may not be so.
Think of something that is 'capable of being shown' — that's what ostensibly means, as it refers to something that appears to be true.