Ordinary language is all right.
One could divide humanity into two classes:
those who master a metaphor, and those who hold by a formula.
Those with a bent for both are too few, they do not comprise a class.
What it means depends.
Some posts from 2012 related to my ongoing thinking about journal-keeping as part of philosophical practice:
Some uses for journals
Recording everything (Robert Shields), new thoughts (Emerson), getting down the present day's work (Bugbee), practicing the waste-book method (Lichtenberg), grounding oneself (Sontag), preparatory studies (Musil), poet's 'biography' (Thoreau), writing an emerging self (Rilke's Malte Laurids Brigge), a record of joy (Thoreau), journal as an other (Thoreau), journal for the other (Dorothy Wordsworth), cultivating the life via the eye (Thoreau). A 'limited philosophical journal' (Cavell).
Technique and form
Sharon Cameron on questions, pictures, and illustrations in Thoreau's journal. Literariness of Thoreau's journal. Interest and occasion, occasion and context. Spiritual exercises. A journal-keeper's review. Returning as someone else. Bugbee on empty word-shells. 'Says I to myself' and remoteness. Thoughts allied to life. Barbara Packer on the blank spaces between Emerson's journal entries. Time and place in Thoreau's journal ('the year is a circle'). A journal's unknown plot. Its form liberates but exposes. Brecht on small works.
A non-isolate self in Muir's Sierra. The Goncourts starting together, carrying on alone. The personal in Bugbee. Cameron on the self in Thoreau's journal. Buell on spirituality in Transcendentalist journals.
Hadot and FoucaultWhy do Hadot and Foucault deny that self-writing is journal-keeping? Foucault on letters and notebooks (their addressees). Hadot reads Marcus Aurelius as addressing a universal audience. Where they disagree about the role of writing in practices of the self. Hadot and the finality of writing.
Learning how to quote, learning how to make yourself suitable to be quoted, aiming at being unquotable or endlessly quotable.
I think these are probably the same people who usually say, '…it comes from the Greek word for "duty"'.
Education as cultivation of various shibboleths.