ɪn klˈæsɪkəl fˈiːld θˈiəɹiz, ðə læɡɹˈæŋɡiən spˌɛsɪfɪkˈeɪʃən ʌvðə flˈoʊ fˈiːld ɪz ɐ wˈeɪ ʌv lˈʊkɪŋ æt flˈuːɪd mˈoʊʃən wˌɛɹ ðɪ əbzˈɜːvɚ fˈɑːloʊz ɐn ˌɪndᵻvˈɪdʒuːəl flˈuːɪd pˈɑːɹsəl æz ɪt mˈuːvz θɹuː spˈeɪs ænd tˈaɪm.
In classical field theories, the Lagrangian specification of the flow field is a way of looking at fluid motion where the observer follows an individual fluid parcel as it moves through space and time.