navigational instrument navigational instrument /ˌnævɪˈɡeɪʃənəl ˈɪnstrəmənt/

noun

1. An instrument used for navigating  ( navigational instrument )
   an instrument used for navigating
    Mariners have always relied on navigational instruments to find their way at sea.
   Mariners have always relied on navigational instruments to find their way at sea.
   
   

 tax collector tax collector /tæks kəˈlɛktər/

noun

1. Someone who collects taxes for the government  ( collector of internal revenue , exciseman , internal revenue agent , tax collector , taxman )
   someone who collects taxes for the government
   
   

 arc light arc light /ɑːrk laɪt/

noun

1. A lamp that produces light when electric current flows across the gap between two electrodes  ( arc lamp , arc light )
   a lamp that produces light when electric current flows across the gap between two electrodes
   
   

 plus plus /ˈplʌs/

adjective

1. Involving advantage or good  ( plus , positive )
   involving advantage or good
    A plus (or positive) factor
   a plus (or positive) factor
   
2. On the positive side or higher end of a scale  ( plus )
   on the positive side or higher end of a scale
    A plus value
   a plus value
    Temperature of plus 5 degrees
   temperature of plus 5 degrees
    A grade of C plus
   a grade of C plus
   

conjunction

1. () And also; in addition  ( plus )
   And also; in addition
   

noun

1. The arithmetic operation of summing; calculating the sum of two or more numbers  ( addition , plus , summation )
   the arithmetic operation of summing; calculating the sum of two or more numbers
    The summation of four and three gives seven
   the summation of four and three gives seven
    Four plus three equals seven
   four plus three equals seven
   
   
2. A useful or valuable quality  ( plus , asset )
   a useful or valuable quality
   

preposition

1. () Added to; along with.  ( and , plus )
   Added to; along with.