The usage (without quibbling too much) of the word "meaning/meaninglessness" is in the commonly understood sense of "purpose/calling/life-objective/etc.". All these are human-defined and therefore "subjective" as life is experienced and lived. There are numerous ways of doing this as is evidenced by the various schools of philosophies/religions/cults/groups etc.
The two viewpoints i.e. 1) Objective view of Life/Existence from the "outside in" vs. 2) Subjective Experiential "inside out" view of Life need to be carefully disambiguated in one's mind.