apacenyë is translated "foresight" in MR:216; yet the context and the form of the word itself clearly indicates that it is not a noun but actually the pl. form of an adjective *apacenya "of foresight". The noun "foresight" is almost certainly *apacen; cf. tercen "insight". (MR:216) The literal meaning of *apacen is *"aftersight", sc. knowledge of that which comes after. [Essi] apacenyë "[names] of foresight", prophetic names given to a child by its mother (MR:216)
n. foresight, (lit.) *after-sight
As suggested by Helge Fauskanger (/apacenyë), the literal meaning of this word is “after-sight”, that is knowledge of that which come after.