Possible Clues:

• Shape with a knife
• Pare shavings, from wood, say
• Do a little woodworking
• Jets designer had to make repeated cuts
• Reduce - jet engine inventor
• Sharpen stick with knife, pare
• Carve
• Shape wood with a knife - inventor of the jet engine
• Trim wood by cutting thin slices from its surface
• Reduce, with ''down''