- cubical quad
- cumulative distribution
- cutoff frequency
- CW laser
- cyano-acetylene
- cyanogens
- cycle counter
- cycle identification
- cycle loss
- cycle redundancy
- cycle reset
- cycle skip
- cyclic carry
- cyclic permutation
- cyclotron frequency
- cyclotronic resonance
- cylindrical antenna
- cypher
- cyphered message
- D-region
- daisy chain
- damage tolerance
- damaged
- dark heat
- data communication
- data constant
- Data Control
- data counter
- data management
- data member
- data packet
- data pile
- data readout
- data recovery
- data separation
- data set
- data sharing
- data stream
- data switching
- data traffic
- data validation
- datagram
- datum point
- de-boost
- deactivation
- dead coil
- dead load
- debugging statement
- decimal notation
- decipherment
- decision block
- decision threshold
- decoding system
- decompiling
- dedicated chip
- dedicated line
- dedicated network
- deep fading
- deerhorn antenna
- default format
- defect density
- defense satellite
- deferred exit
- delay amplifier
- delay composition
- delay generator
- delay line
- delay vector
- delayed order
- delayed port
- delayed response
- delete character
- delete key
- deleter
- damping
- data buffer
- data conversion
- data declaration
- data design
- data domain
- data encoding
- data exchange
- data filter
- data maintenance
- data medium
- data organization
- data transaction
- datum
- deadline
- debtor position
- decoding delay
- decoding relay
- dedicated frequency
- defect annealing
- defective modulation
- deferred entry
- deferred income
- deferred punch
- deferred status
- damping pad